Cryptococcus
Muscle
Cryptococcus: Multifocal Involvement of Muscle
![](../pics/biopsy/inflammation/cryptococus/cryptohelp.jpg)
H&E stain
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Pattern of Infection
Multifocal collections of organisms: Small cryptococcomas
Locations: Endomysium &
Perimysium
Other cell components:
Histiocytes
![](../pics/biopsy/inflammation/cryptococus/cryptohevlp.jpg)
H&E stain
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Cryptococcus: Histiocytic Cell & Cryptococcal foci
![](../pics/biopsy/inflammation/cryptococus/cryptoacpvlp2.jpg)
Acid phosphatase stain
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Pattern of Infection
Histiocytic cells
Associated with cryptococcal clusters
Scattered in endomysium: Probably near capillaries
Locations: Endomysium;
Perimysium
![](../pics/biopsy/inflammation/cryptococus/cryptoacpvlp.jpg)
Acid phosphatase stain
|
![](../pics/biopsy/inflammation/cryptococus/cryptoacpmp2.jpg)
Acid phosphatase stain
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Acid phosphatase: Stains
Cell wall (Rim of cryptococci inside capsule)
Confluent through focus
May obscure cryptococcal organisms
Similar to granulomas associated with foreign bodies or
IMAM
![](../pics/biopsy/inflammation/cryptococus/cryptoacpmp4.jpg)
Acid phosphatase stain
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![](../pics/biopsy/inflammation/cryptococus/cryptcd163lp.jpg)
CD 163 stain
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Histiocytic Cells: Distribution
Foci: Present in clusters along with (around) cryptococci
Scattered: In muscle endymysium near capillaries
![](../pics/biopsy/inflammation/cryptococus/cccd163lp.jpg)
CD 163 stain
|
![](../pics/biopsy/inflammation/cryptococus/cccd163hp.jpg)
CD 163 stain
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Histiocytic Cells: Distribution
Foci: Present in clusters with processes around cryptococci
Cryptococci: Often intacellular within Histiocyte cytoplasm
![](../pics/biopsy/inflammation/cryptococus/cryptcd163hp.jpg)
CD 163 stain
|
![](../pics/biopsy/inflammation/cryptococus/cccd163hp2.jpg)
CD 163 stain
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Cryptococcal Foci
![](../pics/biopsy/inflammation/cryptococus/cryptohemp6.jpg)
H&E stain
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Cryptococcal foci
Locations
Clusters (foci) occur in: Endomysium or
Perimysium
Contents
Some foci contain mainly cryptococci, connective tissue & indistinct cells that stain for acid phosphatase (Above).
A few foci contain clusters of lymphocyte-like cells (Below)
Neighboring muscle fibers
Often smaller than in other areas
![](../pics/biopsy/inflammation/cryptococus/cryptohehp6.jpg)
H&E stain
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Some cryptococcal foci contain clusters of lymphocyte-like cells
![](../pics/biopsy/inflammation/cryptococus/cryptocrhp.jpg)
Congo red stain
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Cryptococcal focus
Fewer cryptococci
More other cells & tissue
![](../pics/biopsy/inflammation/cryptococus/cryptohemp7.jpg)
H&E stain
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Cryptococci: Organisms
Cryptococci: Many budding
![](../pics/biopsy/inflammation/cryptococus/ccorgshehp.jpg)
H&E stain
|
![](../pics/biopsy/inflammation/cryptococus/cryptohehp4.jpg)
H&E stain
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Cryptococcus: Organisms
Sizes: Varied
Structure
Peripheral: Clear capsule with varied thickness
Central
Rimmed circular region
A few show budding (Arrows, Below)
![](../pics/biopsy/inflammation/cryptococus/cryptohemp5ar.jpg)
H&E stain
|
![](../pics/biopsy/inflammation/cryptococus/cryptmucicarminelp.jpg)
Mucicarmine stain
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Mucicarmine: Stains cryptococcal organisms
![](../pics/biopsy/inflammation/cryptococus/cryptmucicarminemp.jpg)
Mucicarmine stain
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![](../pics/biopsy/inflammation/cryptococus/cryptcdgmslp.jpg)
Grocott methenamine silver (GMS) stain
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Grocott methenamine silver: Stains cryptococcal organisms
![](../pics/biopsy/inflammation/cryptococus/cryptcdgmsmp.jpg)
Grocott methenamine silver (GMS) stain
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![](../pics/biopsy/inflammation/cryptococus/cryptocappashp.jpg)
PAS stain
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Cryptococcus: Organisms
Sizes: Varied
Structure
Peripheral: Clear capsule with varied thickness
Central: Rimmed circular region, PAS+
Clustered in endomysium or perimysium
![](../pics/biopsy/inflammation/cryptococus/cryptopashp.jpg)
PAS stain
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Cryptococcal cluster: Most organisms in this cluster have thin, or no, capsules
![](../pics/biopsy/inflammation/cryptococus/cryptocapnopashp3.jpg)
PAS stain
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Alcian blue: Stains central region of organisms
![](../pics/biopsy/inflammation/cryptococus/cryptoalbl.jpg)
Alcian blue stain
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Sudan black: Stains round area within central region of some organisms
![](../pics/biopsy/inflammation/cryptococus/cryptosudan.jpg)
Sudan stain
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Thin layer of connective tissue around cryptococci
Stained by Gomori trichrome
![](../pics/biopsy/inflammation/cryptococus/cryptogtmp.jpg)
Gomori trichrome stain
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Cryptococci contain no mitochondria
![](../pics/biopsy/inflammation/cryptococus/cryptocoxmp.jpg)
COX stain
Cryptococci: Ultrastructure
![](../pics/biopsy/inflammation/cryptococus/cryptemlp2.jpg)
From: R Schmidt
|
![](../pics/biopsy/inflammation/cryptococus/crypthistem2.jpg)
From: R Schmidt
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![](../pics/biopsy/inflammation/cryptococus/cryptemhp5.jpg)
From: R Schmidt
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![](../pics/biopsy/inflammation/cryptococus/cryptemhp3.jpg)
From: R Schmidt
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![](../pics/biopsy/inflammation/cryptococus/cryptemhp4.jpg)
From: R Schmidt
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![](../pics/biopsy/inflammation/cryptococus/cryptemhp2.jpg)
From: R Schmidt
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![](../pics/biopsy/inflammation/cryptococus/cryptemhp7.jpg)
From: R Schmidt
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![](../pics/biopsy/inflammation/cryptococus/cryptemhp6.jpg)
From: R Schmidt
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![](../pics/biopsy/inflammation/cryptococus/cryptemhp8.jpg)
From: R Schmidt
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Cryptococcus within a Histiocyte
![](../pics/biopsy/inflammation/cryptococus/crypthistem.jpg)
From: R Schmidt
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![](../pics/biopsy/inflammation/cryptococus/crypthistvacs2.jpg)
From: R Schmidt
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![](../pics/biopsy/inflammation/cryptococus/cryptemvacs.jpg)
From: R Schmidt
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C5b-9 deposited on tissue within and surrounding a cryptococcal focus
![](../pics/biopsy/inflammation/cryptococus/cryptoc5b9b.jpg)
C5b-9 stain
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Cryptococcal myopathy: Muscle fibers
![](../pics/biopsy/inflammation/cryptococus/cryptogtmp3.jpg)
Gomori trichrome stain
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Muscle fibers in cryptococcal myopathy
Diffuse atrophy
Smallest muscle fibers are located at edge of fascicles near cryptococcal focus
![](../pics/biopsy/inflammation/cryptococus/cryptovvglp.jpg)
VvG stain
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![](../pics/biopsy/inflammation/cryptococus/cryptogtmp2.jpg)
Gomori trichrome stain
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Muscle fibers in cryptococcal myopathy
Diffuse atrophy
Fiber sizes: Varied
![](../pics/biopsy/inflammation/cryptococus/cryptovvgmp.jpg)
VvG stain
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![](../pics/biopsy/inflammation/cryptococus/cryptovvgmp2.jpg)
VvG stain
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Cryptococcal myopathy
Muscle fibers
Diffuse atrophy
Fiber sizes: Varied
Smaller fibers at edge of fascicle near damaged perimysium
NADH stains small fibers dark (Below)
![](../pics/biopsy/inflammation/cryptococus/cryptonadhlp2.jpg)
NADH stain
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![](../pics/biopsy/inflammation/cryptococus/cryptocoxhp2.jpg)
COX stain
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Cryptococcal myopathy: Mitochondrial pathology
Megaconial: Most mitochondria are large
Some COX- muscle fibers are present
![](../pics/biopsy/inflammation/cryptococus/cryptocoxhp3.jpg)
COX stain
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Type 2 fiber predominance
![](../pics/biopsy/inflammation/cryptococus/cryptoatp43mp.jpg)
ATPase pH 4.3 stain
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MHC Class I: Upregulated on surface of all muscle fibers
![](../pics/biopsy/inflammation/cryptococus/cryptomhc1.jpg)
MHC Class I stain
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Cryptococcus: Perimysial connective tissue involvement
![](../pics/biopsy/inflammation/cryptococus/cryptohelp5.jpg)
H&E stain
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Cryptococcal foci within perimysial connective tissue
Some foci contain mostly cryptococcal organisms (Above)
A few foci contain cells and cryptococci (Below)
![](../pics/biopsy/inflammation/cryptococus/cryptohelp4.jpg)
H&E stain
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Histiocytes are present in
Perimysial cryptococcal foci
Endopmysium: Scattered
![](../pics/biopsy/inflammation/cryptococus/cryptoacplp2.jpg)
Acid phosphatase stain
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![](../pics/biopsy/inflammation/cryptococus/cryptoalplp2.jpg)
Alkaline phosphatase stain
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Alkaline phosphatase stains
Perimysial connective tissue
Endomysial capillaries
![](../pics/biopsy/inflammation/cryptococus/cryptoalpmp.jpg)
Alkaline phosphatase stain
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Capillary pathology
![](../pics/biopsy/inflammation/cryptococus/cryptoulex.jpg)
UEA 1 stain
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Endomysial Capillaries
Large & Abundant (Above)
C
5b-9 staining (Below)
Also see:
Endoneurial microvessel staining
![](../pics/biopsy/inflammation/cryptococus/cryptoc5b9.jpg)
C5b-9 stain
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![](../pics/biopsy/inflammation/cryptococus/cryptemvesslp.jpg)
From: R Schmidt
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![](../pics/biopsy/inflammation/cryptococus/cryptemvessmp.jpg)
From: R Schmidt
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Cryptococcal infection: Associated Neuropathy
![](../pics/biopsy/inflammation/cryptococus/cryptonvhe.jpg)
H&E stain
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Endoneurium & Perineurium: Normal structure
No cryptococcal infection
![](../pics/biopsy/inflammation/cryptococus/cryptonvgt.jpg)
Gomori trichrome stain
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Myelinated axons: Markedly reduced in number
![](../pics/biopsy/inflammation/cryptococus/cryptonvvvg.jpg)
VvG stain
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![](../pics/biopsy/inflammation/cryptococus/cryptonvacp2.jpg)
Acid phosphatase stain
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Histiocytes
Few scattered in endoneurium
Some in epineurium, especially near vessels
![](../pics/biopsy/inflammation/cryptococus/cryptonvacp.jpg)
Acid phosphatase stain
|
![](../pics/biopsy/inflammation/cryptococus/cryptonvvessacp.jpg)
Acid phosphatase stain
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C5b-9
Mild staining on endoneurial microvessels
Also see:
Endomysial capillary staining
![](../pics/biopsy/inflammation/cryptococus/cryptonvc5b9.jpg)
C5b-9 stain
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Return to
Cryptococcus
5/15/2023